Clutch



Jan. 14, 1936; F. J. LAPOINTE I CLUTCH Original Filed Feb. 21, 1951 Patented a... 14, 1936 UNITED- STATES PATENT OFFICE Original application February 21, 1931, Serial No.

517,386, new Patent No. 1,937,121, dated November 28, 1933.

Divided and this application November 25, 1933, Serial No. 699,737

1 Claim. (01-279-74) V Fig. 1 is a perspective view of a drawhead of r The object of my invention is to provide a tool clutch for securing a; tool in a machine in such a-manner as to enable ready or automatic.

, clutching of the tool and ready or automatic 5 declutching or disconnection. The invention may be used in a machine of a variety of forms and for many purposes. It may be used for example, in breaching machines wherein the clutch may be used as a part of the drawhead or press head, depending on whether the breach used is:

a pull breach or a push breach. In either case automatic means for disengaging the head of a breaching tool from the operative head of the machine may be provided, as,\for example, to

permit the breachingtool to. bdeposited in a socket upon completion of its working stroke and separate the breach .frem the drawhead erthe work plate so that the material to be worked on' may be inserted betweenthe breaching tool andthe operative head of the machine or its work plate.

The clutch of myinventien automatically en-i and shearing action on the breaching tool by the work during the cutting or working stroke,

thereby increasing the eflicieney of the breaching machine, as disclosed in application Serial No. 517,386, filed February 21, 1931, now Patent No. 1,937,121, issued November 2 8,- 1933, of which 40 this is a divisional application.

The invention consists in other features and advantages which will appear from. the following description and upon-examination of the drawing. The structure containing the inventien may partake of difierent forms and still embody the invention. To illustrate a practical,

,application of the clutch of my invention, I have selected a drawhead of the type commonly used in breaching machines as an exampleof the 5 0 various structures and details thereof that con tain the invention, it being understood that variations may be made without departing from the -spirit of the invention. The particular clutch referred to is shown in the accompanying drawing and is described hereinafter.

a breaching machine and the end of a breaching tool. Fig. 2 is a sectional view of the drawhead. Fig. 3 is a cross-section taken on the plane of the line 3-3 shown in Fig. 2.

5 The drawhead I is adapted to be positioned on a bracket 2 that may be connected to, or form a part of, a drawplate of a breaching machine. One end ofthe drawhead I has a threaded stem 5.- The stem 5 is threaded into the bracket 2 and secured thereto by a nut I. The drawhead may thus be reciprocated by the reciprocation of the plate during the operation of the breaching machine.

A breaching tool I0 isprovided with ahead lI having sloping er bevelled edges l2 and a neck I3 which a smaller diameter than the head II and is adapted to be engaged by a plurality of slideable do 5 positioned in the drawhead I. The 'slicleable and are so formed as te extend into the socket I6 of the drawhead to engage the neck I3 oiLthe breaching tool It and lock the head II of the breach in the socket I6; The dogs I5 are located in openings formed in the wall I8, produced by the formationei the socket I6 in the drawhead, and are engaged by a shell 20 that surrounds the drawhead I. Due to the construction of' the breach head, the breach will be rigidly imain tained in the socket by the dogs, notwithstanding vibrations of the machine and the tensien'stress on the breach during the cutting stroke.

In order that the head of the breaching tool I0 may be released from the socket I6, the shell 2ll-is provided with a recessed portion 22 which, when placed in registering relation to the dogs, enables the outward movement of the dogs I5 with respect to the head II of the breach by the lateral pressure produced by the inclined surfaces of the bevelled edges |2 of the head II. The breach is thus released, when the recessed portien22- is aligned with the dogs I5, by movement of the dogs with respect to the recessed portion.

The shell '29 is spring pressed by a helical egs I5 are movable 1 radially with'respect to the axis of the drawhead spring 23 which is located intermediate a shoulhead I when the shell has been moved relative to the drawhead by the spring 23-to cause abutment of the shoulders 21 and 23.

The recessed portion 22 of the shell 20 has an inclined surface 32. Each of the dogs I5 is provided with a similarly inclined surface 33. When the dogs l5 are moved radially, the inclined surfaces 32 and 33 of the recessed portion '22 and the dogs I5, respectively, are slideably engaged. The-recessed portion 22 of the shell 20 is so located that when the shell 20 is depressed by the operation of the spring 23, the dogs will be forced from the recess 22 to engage the head ll of the broaching tool It], the outward movement of the dogs from the recessed portion being facilitated .by the slideable relationship of the inclined surfaces 32 and 33 of the recessed portion and the dogs. The dogs i5 will be engaged as against outward movement with respect to the broach head by a portion 24 of the shell 20 which has a diameter substantially less than that of the inner surface of the 1 recessed portion 22, and the diameter of the portion 24 of the shell is such as to cause the ends 30 of the dogs I5 to protrude into the socket ii to engage the head H of the broaching tool and lock the head of the broach in the socket of the drawhead. V

In order to facilitate the insertion of the broach head into the socket and the engagement of the head by the dogs, and to facilitate the disengagement of the broach head from the dogs, the ends 33 of the dogs 15 are provided with upper and lower bevelled edges 3|. Due to the slideable inter-relation of the bevelled surfaces l2 and3l of the head II and the ends 30 of the dogs l5, respectively, an outward pressure will be exerted on the dogs by the head of the broaching tool during its insertion or its weight during its withdrawal from the socket of the drawhead.

Due to the diameter of the shell and presence of the recessed portion 22 in the inner wall of the shell, the movement of the dogs l5 outwardly with respect to the head of the broaching tool will be permitted or'resisted, depending upon the relative location of the shell 20 with respect to the drawhead I. If the shell is so located with respect to the drawhead that the recessed portion 22 is located in a position to receive the dogs IS, the dogs may be moved outwardly with respect to the broach head to release the broaching tool when there is a downward pull resulting either from the weightof the tool itself or a definite external pull; If the shell is so located with respect to the drawhead that the recessed portion 22 is in a position to receive the drugs I5 and it is desired to insert the broaching tool in the socket IS, the dogs are moved radially with respect to the axis of the broach when the broach head is inserted in the drawhead, which permits the broach to seat itself in the socket, the radial movement of the dogs with respect to the axis of the broach being readily achieved by reason of the'slideable inter-relation of the bevelled surfaces 3i of the ends 30 of the dogs. Subsequent downward movement of .the shell 20 by reason of the pressure of the spring 23 will move the recessed portion 22 longitudinally with respect to the drawhead and will force the dogs l5 inwardly to engage the neck I3 of the broach l0 andsecure the head of the broaching tool within the socket. The head of the broach will thus be rigidly engaged in the socket of the sembled with respect to other parts of the broaching machine that when the drawhead is moved downwardly, the lower edge of the shell 20 may be engaged by a member such as the plate or bracket 35, or other suitable means, which will operate to prevent further movement of the shell 20 while the broach head i moves downwardly with respect to the shell. The pre vention of movement of the shell during the downward movement of the drawhead positions the recessed portion of the shell so that it is located in alignmentwith the dogs 15 and so that the weight of the broach or a downward pressure externally applied to the broach will move the dogs radially with respect to the axis of the broach into the recessed portion 22 of the shell 20, due to the slideable inter-relation of the bevelled surfaces ll of thehead of the broach and the surfaces 3| of the ends 30 of the dogs andthe slideable inter-relation of the inclined surfaces 33 of the dogs and the inclined surfaces 32 of the recessed portion.

The broach, when released from the drawhead, may be guided into a suitable socket or recessed portion, and the work may be positioned on a work plate between the broach head and the drawhead. The broaching tool may then be lifted ,and inserted into the drawhead by suitable means, the said means lifting the broach upwardly into the socket l6 of the drawhead. In the event that the dogs l5 have been worked into the socket by machine vibration or otherwise, the upward movement of the broachhead will force the dogs outwardly with respect to the drawhead and into the recessed portion 22 of the shell 20, and the said means will operate to maintain the broach head in its position within the socket until the upward stroke of the drawhead has moved the shell 20 so that its lower edges are no longer engaged by the deflector plate 35. The spring 23 then forces the shell downwardly with respect'to the drawhead as the drawhead is raised until the shoulders 21 and 28 of the shell and drawhead are in abutting relation. The relative downward movement of the shell with respect to the drawhead forces the dogs l5-from the recessed portion 22 and forces the ends 30 of the dogs l5 into the socket l6 to engage the neck l3 of the broaching tool I and thus locate the broach in the drawhead. Continued upward movement of the drawhead causes the broach to complete its cutting or working stroke.

I claim:

In a clutch for a tool having a neck, a shank and a head, the head having oppositely disposed angular beveled surfaces, a cylindrical clutch block having a socket for receiving the head of a tool, the head having beveled surfaces, a cylindrical clutch block having a socket for receiving the head and a part of the shank of the tool, the clutch block having openings, radially slidable dogs located in the openings, a shellthe cylindrical surface of the clutch block and forming an auxiliary guiding surface, the clutch block having a circular shoulder at its upper end and engaged by the said flange and fitting the interior surface of the shell, the lower end of the shell extending below the clutch block, the clutch block having a circular protruding part and the shell having a protruding shoulder, a helical spring located between the said part and the said protruding shoulder for yieldingly resisting movement of the shell relative to the clutch block, the shell having a ircular recess for receiving the outer ends or the dogs to release the tool when the shell is moved' counter the pressure of the spring.

FRANCIS J. LAPOINTE. 

